Replace Old Acrylic Dome Skylights with VELUX Glass Skylights
Upgrade tired, yellow, brittle or leaking acrylic dome skylights with modern double-glazed VELUX flat roof skylights, custom flashing and a cleaner internal finish.
Modern glass replacement. The VELUX FCM is a popular fixed glass skylight for replacing older acrylic dome skylights on flat and low-pitch roofs.
Old Acrylic Domes Were Common — But They Do Not Age Well
Many Melbourne homes still have old acrylic or plastic dome skylights. They were a common way to bring light into flat roof extensions, bathrooms, hallways, laundries and living areas.
Over time, acrylic domes can become cloudy, yellow, noisy in rain, brittle, cracked, poorly sealed or visually dated. Some still bring in daylight, but the room may feel dull because the old dome and diffuser no longer provide a clean, clear light path.
Replacing the old dome with a modern VELUX glass skylight can improve the look of the roof, brighten the room and create a cleaner finish inside the home.
Common signs your dome is ready to replace:
- Yellow, cloudy or brittle acrylic
- Cracks, crazing or visible sun damage
- Water staining around the shaft or ceiling
- Old silicone patches or temporary repairs
- Rusty, damaged or poorly fitted flashing
- Noisy rain or strong heat build-up below
- Outdated internal diffuser or ceiling surround
Old Acrylic Dome vs Modern VELUX Glass Skylight
A dome replacement is not just a roof repair. It can be a full daylight upgrade, especially when the old plastic dome, shaft and diffuser are holding the room back.
Typical issues
- Plastic can yellow or go cloudy over time
- Older domes may feel dated from inside and outside
- Single-skin plastic can perform poorly compared with modern glazing
- Old seals and flashings may have been patched many times
- Diffusers and ceiling trims can reduce the quality of daylight
Modern upgrade
- High-performance double-glazed glass
- Cleaner low-profile roof appearance
- Approx. 99% UV protection and approx. 70% radiant heat block
- NEAT coating to help reduce cleaning frequency
- Modern internal finish when paired with a neat plaster shaft
Why We Often Recommend VELUX FCM for Dome Replacement
The VELUX FCM fixed flat roof skylight is one of the most practical replacements for many old acrylic dome skylights. It is designed for flat and low-pitch roofs and gives the home a cleaner, more modern glass finish.
It does not open, so it is best when your main goal is more natural daylight rather than ventilation. For bathrooms, kitchens, laundries, hallways, living areas and flat roof extensions, it can be a strong upgrade from an old plastic dome.
- Suitable for roof pitches from 0° to 60° when correctly installed
- High-performance double glazing as standard
- Laminated inner pane and toughened outer pane
- Cleaner low-profile appearance on the roof
- Available in 14 sizes for different openings and rooms
- Can be installed portrait, landscape or selected custom orientations depending on size and job conditions
Fixed, Manual or Solar Opening Replacement?
Most old acrylic domes are replaced with fixed glass skylights, but some rooms benefit from an opening model for fresh air.
| Replacement Option | Best For | Good to Know |
|---|---|---|
| VELUX FCM Fixed Flat Roof Skylight | Natural daylight only | The most common glass upgrade when you do not need ventilation. Great for hallways, living rooms, bedrooms, robes, laundries and rooms with existing airflow. |
| VELUX VCM Manual Opening Flat Roof Skylight | Daylight plus manual ventilation | A good option for rooms that need fresh air and where manual operation suits the window position. |
| VELUX VCS Solar Opening Flat Roof Skylight | Daylight plus remote ventilation | A strong upgrade for out-of-reach areas or rooms where easy ventilation control is important. Includes remote operation and rain sensor features. |
Custom Flashing Matters More Than the Skylight Itself
A flat roof skylight is only as good as the flashing and waterproofing around it. This is especially important when replacing an old dome.
Existing Opening
The old dome size, throat size, upstand and roof opening all need to be checked. A VELUX replacement may need an adaptor, new framing or modified shaft.
Roof Pitch
Flat and low-pitch roofs need careful drainage planning. On very low pitch roofs, installation method and flashing detail become even more important.
Roof Material
Metal deck, membrane roof, tiled surrounds and custom roof details can all affect how the replacement skylight should be flashed.
Popular VELUX FCM Sizes for Dome Replacement
The correct replacement size depends on the existing dome, the internal shaft, roof structure and flashing. These VELUX FCM sizes are common starting points when matching old acrylic dome skylights.
Our Dome Replacement Process
We make the replacement process clear before installation day, so you know what product is being used and what finish is included.
Send Photos
Send photos of the old dome from outside, the ceiling/shaft from inside, and the room below. Measurements are helpful too.
Check Suitability
We review the roof type, old dome size, shaft, likely flashing and whether fixed, manual or solar opening is the best choice.
Recommend Product
We recommend the right VELUX model and size, plus whether custom flashing, adaptor work, framing or plastering is required.
Remove Old Dome
The old acrylic dome, old trims and unsuitable flashing are removed as required so the roof opening can be prepared properly.
Install New Skylight
The new VELUX skylight is installed with the correct flashing and waterproofing detail for your roof and replacement situation.
Finish Inside
Where included, the internal shaft or ceiling finish is tidied, framed or plastered for a cleaner modern result.
Should You Repair the Old Dome or Replace It?
Sometimes a small leak appears to be a simple sealant issue. But with older acrylic dome skylights, patching can become a short-term cycle: more silicone, more staining, more call-backs, and no real improvement to the look or performance of the skylight.
Replacement is usually worth considering when the dome is old, brittle, yellow, cracked, poorly flashed or no longer suits the renovated room below.
- Replace if the acrylic is cloudy, yellow or cracked
- Replace if the flashing has been patched many times
- Replace if the ceiling shaft is old or unattractive
- Replace if you want a cleaner glass look
- Replace if you are already renovating the roof or room
When a repair may not be enough
If the old skylight has water staining, brittle plastic, damaged flashing or a poor roof fall around it, simply resealing the top may not fix the underlying problem.
A proper replacement gives the opportunity to review the whole system: roof opening, flashing, skylight, shaft and internal finish.
Send Photos for AdvicePopular Rooms for Acrylic Dome Replacement
Old dome skylights are often found in extensions, bathrooms, hallways and older flat-roof areas. Replacing them can make the whole room feel cleaner and more modern.
Bathrooms
Upgrade old yellow domes and improve the feeling of natural light in bathrooms, ensuites and powder rooms.
Hallways
Replace dull plastic skylights and bring cleaner daylight into dark internal corridors.
Kitchens
Modernise older kitchen skylights with a glass VELUX finish and improved shaft detail.
Living Areas
Refresh old extension skylights and make flat-roof living spaces feel brighter and more premium.
How Much Does Acrylic Dome Replacement Cost?
The cost depends on more than the new skylight size. With old dome replacements, the existing roof opening, flashing, shaft and internal finish can all affect the job.
- VELUX fixed, manual or solar opening model
- Size of the old dome and new replacement skylight
- Whether the opening is a direct fit or needs modification
- Roof pitch, roof material and drainage around the skylight
- Custom flashing and waterproofing requirements
- Single-storey or double-storey roof access
- Condition of the internal shaft and ceiling
- Whether framing, plastering or finishing work is included
Want a quicker estimate?
Send clear photos of the dome from the roof, the inside ceiling/shaft, and the room below. Include rough measurements if you have them.
We can usually tell you what information is still needed and whether a VELUX glass replacement is suitable.
Important Notes Before Replacing a Dome Skylight
Every old dome is different. Before ordering a replacement, the existing skylight, roof and ceiling should be checked properly.
Direct Replacement Is Not Always Guaranteed
Some common dome sizes can be closely matched, but the existing curb, opening and shaft still need to be checked.
Old Water Damage Should Be Inspected
If there are stains, soft plaster, swollen trims or repeated leaks, the surrounding area may need more than a simple skylight swap.
Permits May Depend on the Job
Permit requirements can depend on council area, roof structure, heritage overlays, owners corporation rules and the amount of structural work involved.
Melbourne’s VELUX Dome Replacement Team
We do more than sell a glass skylight. We help match the right VELUX product, flashing and installation method to the old dome, roof and room below.
VELUX Product Knowledge
We help compare FCM fixed, VCM manual opening and VCS solar opening flat roof skylights for your replacement job.
Custom Flashing Support
Old dome replacements often need careful flashing. We can advise on the correct flashing approach for your roof type and pitch.
Complete Installation
Where required, we can help with roof work, framing, internal shaft improvements and plastering for a cleaner finished result.
Acrylic Dome Skylight Replacement FAQs
Can I replace an old acrylic dome skylight with a VELUX skylight?
In many cases, yes. VELUX FCM fixed flat roof skylights are a popular replacement for old acrylic domes. Suitability depends on the old dome size, roof opening, roof pitch, flashing and internal shaft.
Is a VELUX FCM better than an old acrylic dome?
For many homes, yes. The VELUX FCM uses high-performance double-glazed glass, has a cleaner low-profile appearance, and does not yellow like old acrylic plastic domes.
Does the VELUX FCM open?
No. The FCM is a fixed skylight for natural daylight only. If you need ventilation, ask us about VELUX VCM manual opening or VELUX VCS solar opening flat roof skylights.
Can the old dome be replaced without changing the ceiling shaft?
Sometimes, but not always. It depends on the existing shaft size, condition, shape and how the new skylight aligns with the roof opening. Some jobs need shaft or plastering work for the best result.
Do I need custom flashing?
Yes. VELUX flat roof skylights require custom-made flashing. This is especially important when replacing an old dome because the existing opening and roof detail may not suit a standard approach.
Can you replace a leaking dome skylight?
Yes. We can inspect the old dome, roof photos and ceiling condition, then advise whether replacement with a VELUX skylight is suitable. If there is existing water damage, extra repair or plastering work may be needed.
What photos should I send for a quote?
Please send photos of the old dome from outside, the ceiling or shaft from inside, the room below, and any visible water stains or damage. Rough measurements of the dome and internal opening are also helpful.
Do I need a permit to replace an old dome skylight in Victoria?
Permit requirements depend on the property, council area, roof structure, owners corporation rules, heritage controls and the amount of structural work involved. Homeowners should check with their local council or a registered building surveyor if unsure.
Ready to Replace Your Old Acrylic Dome Skylight?
Send us photos of your old dome, roof and ceiling. We will help you choose the right VELUX glass skylight, custom flashing and installation package for your Melbourne home.